1. Field of the Invention
This invention relates in general to the field of air blower motor assemblies and in particular to a mounting and sealing arrangement for an air blower motor and fan assembly designed for high output, leak free and quiet operation.
2. Description of the Prior Art
An air blower, in its simplest version is a fan which moves or blows air in a forward direction. A fan consists of a motor having blades which extend perpendicular from the shaft of the motor and have a bi-directional twist along their length. By reversing the direction of rotation of the motor, the fan would blow air in a backward direction. As an alternative, the pitch of the fan blades may be used to set and change the direction of the moving air. Another type of prior art air blower uses impeller blades which draw air in from a center opening, forces it outward, and is then channeled in a desired direction. Such prior fans find use in cooling electrical components cooling the motor itself, in air conditioners to liquefy the compressed gas, in automobiles to blow air past radiators, and many other like applications.
In the event that the moving air is desired to be more directed, an encasement is placed around the fan blades and the motor. An air inlet is provided at one end of the casing and an air outlet is provided at the other end of the casing. A tube or hose is then connected to the air outlet, which allows the air to be directed to a particular location or in a more concentrated direction. For example, a leaf or grass blower is one such application. A vacuum cleaner is another example, but the direction of airflow is reversed. In these shrouded or encased fan applications, radial impeller vanes are generally used rather than fan blades. Radial vanes provide a smaller overall package and allow for higher flow rates and higher pressures.
In an encased blower arrangement and where the airflow is axial, a seal is advantageously used to separate the inlet side of the casement from the outlet side. Without a dividing seal, the air can circulate within the casing rather than being blown out of the outlet part. The air would simply take the path of least resistance. Thus, in practice, in order to maximize the efficiency of an air blower, it is desirable to have the most effective seal possible, which in certain applications takes the form of making the casing in two parts, a front portion, and a back portion. The seal is placed between two portions of the casing and in some manner is attached to the motor and fan assembly within the casing.
In a low volume, low pressure encased fan arrangement, a simple seal is all that is necessary to maintain the separation of the pressure side of the casing from the vacuum or suction side of the casing. However, when a large volume of air is required to be blown or moved within the casing, and or high pressure is required, the seal becomes problematic. Moreover, when it is necessary or desirable to minimize the size of the casing, the sealing becomes even more problematic because of the large pressure differential that results between the suction side and the pressure side within the casing. The pressure differential tends to unseat the seal rendering it ineffective or inefficient. This prior art problem is solved by the present invention.
Another problem present in the prior art air blower assemblies is the existence of noise when the unit is in operation. Moving large volumes of relatively high pressure air creates substantial noise. The causal factor being the difficulty in isolating the fan and motor within the casing from the casing itself. The present invention also overcomes this prior art problem.
The present invention accomplishes the above-stated objectives as well as others, as may be determined by a fair reading and interpretation of the entire specification herein, which comprises an air blower having a combination seal and motor mount. The seal effectively seals between casing halves and between the suction and pressure sides of the motor and the fan assembly. Moreover, the seal serves to acoustically isolate the motor and fan assembly from the casing and substantially reduces the noise associated with the air blower.